A structure, in which an annular baffle plate for reducing flow noise is fixed by spot welding to a tank bottom wall, is disclosed in Patent Document 1 (Japanese Utility Model Application Laid-Open (JP-U) No. H05-56553) as a fuel tank that is installed in an automobile. Note that, as a fuel tank, there is the structure disclosed in Patent Document 2 (Japanese Patent Application Laid-Open (JP-A) No. 2006-232132).